The cylinder escapement is satisfactory from the point of view of safety, but it has two significant weak points:
it is not a detached escapement, i.e. one of the teeth of the escape wheel is constantly in contact, and therefore in friction, with the balance wheel. This friction disrupts the oscillations, reduces the efficiency of the escapement and impairs chronometric properties;
it is not a constant force escapement. The energy transmitted to the balance wheel depends on the torque from the escape wheel.